Feather Growth and Condition

The mechanisms behind feather growth are very counter-intuitive. Feathers begin to grow at the tip of the feather, the part which, in House Finches, is pigmented. The barbs grow in shafts and collect at their base to form the rachis. This development occurs "in pin" in the bird's dermis. The feather then rolls out and spreads, creating the shape that we recognize.

Because we know the way in which feathers develop, we are able to track the rate of growth of a feather months after the bird's molt. For my project, I take a look into the past and use trigonometry and feather landmarks to find what that feathers rate of growth was during the bird's molt.

I'm going to compare this rate of feather growth to the bird's condition (based upon the mass taken at time of capture). Will birds in worse conditions grow feathers more quickly (hastily) or will they take longer to find the energy to grow the feathers? The most interesting part of this question I will be investigating is the different results between sexes.

Males put much more energy into their feathers, especially House Finches. They must expend extra energy to not only put carotenoids into their feathers but also to modify the carotenoids in their diet to determine their hue and reflectance. I predict that there will be a larger deviation of feather growth vs. condition in males when compared to females because males spend more energy growing their feathers.

I look forward putting out some significant data soon!

Thanks for reading,
Caitlin